Piperin

Colourless liquid with a characteristic ammo-niacal smell m.p. 9 C, b.p. 106°C. Miscible with water. It is present in pepper as the alkaloid piperine from which it can be obtained by healing with alkali. It can also be prepared by the reduction of pyridine, either electrolytically or by other means. Piperidine is a strong base, behaving like the aliphatic amines. 

CgHeOa. White crystals m.p. 37°C, b.p. 263°C. Occurs associated with vanillin. Obtained on oxidation of various natural products such as piperine. Used extensively in soap perfumery. 

With the introduction of improved analytical techniques, starting around 1817, the evaluation of dmgs began and, over a span of about 10 years, strychnine (13, R = H), emetine (14), bmcine (13, R = OCH3), piperine (15), caffeine (16), quinine (17, R = OCH3), colchicine (4), cinchonidine (17,... 

Synthetics. The lack of spice products to satisfy demand and the wide variation in price and availabihty have caused the manufacture of selected synthetics, chemically identical to the component in the natural spice, to replace the vital components of some spices. However, synthetic organic chemistry is not yet able to manufacture economically the many homologous piperine [94-62-2] components in black pepper or those capsaicin [404-86-4] amides in... 

Anderson first hydrolysed piperine by alkalis into a base and an acid, which were named by Babo and Keller piperidine and piperic acid respectively. The chemistry of these products is so well known that it need not be discussed here. The alkaloid was synthesised by Rugheimer by the action of piperoyl chloride on pijieridine. 

Pyridine Group. Piperine, Piperovatine, Leucenol, Mimosine, Alkaloids of Ricinus communis, Foenugrec, vy eca Nut, Hemlock, Lobelia, Tobacco (Nicotiana spp.). Anabasis aphylla, Pomegranate Root Bark. ... 

UV irradiation of piperine, the most important hot substance of pepper, does not lead to the incorporation of atmsopheiic oxygen [8]. The all-trans compound is converted to the cis-trans isomer, this can be seen in the chromatogram above the all-rrans piperine (Fig. 16). 

Fig. 16 Detection of cis/trans isomerization of piperine by the SRS technique after UV irradiation (A) originai chromatogram, (B) schematic representation.

F], Fj = mobile phase front after development in the first and in the second dimension a, b, c = positions of application of the //a/w/tm/w-piperine before the first (ID) and before the second development 2D -A" = cis/tmiis-piperine, = trans/lrans-pipenn O = position of the tmns/ trans-piperine after the first development. Irradiation of the chromatogram with long-wavelength UV light after application of trans/lrans-pipeiine to position b after the first development (position c was not irradiated ). 

The interactions between the endocrine and neural systems of the GIT are complex, include shared signaling molecules, and can be hard to separate. Therefore, it is likely that the influence(s) of some phytochemicals will cross over between neural and non-neural pathways. Corresponding with this, lumenal administration of capsaicin interacts with visceral neurons to increase GIT motility (Zittel et al., 2001 Topcu et al, 2002) and abrogates the decreased electrolyte and fluid secretion caused by piperine (Capasso et al., 2002). 

Otera and coworkers developed an alternative procedure to the Julia method for generating dienes or alkynes in the same reaction by the double elimination of /J-acetoxy or /1-alkoxy sulphones with potassium /-butoxide (equation 58)98,99. The reaction pathway leading to the diene or an alkyne depends on the substrate structure and the reaction conditions. If an allylic hydrogen is present in the substrate then diene is formed, otherwise, the alkyne is the product of the reaction. This modified Julia methodology has een applied to the synthesis of vitamin A (equation 59)100, alkaloids piperine (equation and trichonine (equation 61)102. 

The chemistry of pepper has long been studied and the pungent principle of black pepper—a piperidine alkaloid, piperine 134—was isolated as early as 1877 (201). Its synthesis from the acid and piperidine was accomplished in 1882. (202). The corresponding pyrrolidine alkaloid trichostachyne (135) was isolated some 100 years later from several Piper species (see below). The cooccurence of piperidine and pyrrolidine alkaloids is a common feature of the chemistry of pepper. In many cases, the crude alkaloid extract is first cleaved with acids or bases and then each alkaloid is reconstituted by selective amidation. For the sake of unity, this chapter will be limited to comments on pyrrolidines, even in cases where they are minor alkaloids. 

Piper guineense Schum. and Thonn is a creeper found in humid and shady forests from Guinea to Uganda and Angola it is known as the source of the Ashanti pepper. Its fruit and roots contain the above-mentioned piperine 134 and trichostachyne (135) (203, 204). In the root was also found wisanidine (136) named after the Nigerian vernacular name of the species, wisa osoro (205). The... 

Bu ) have been used to induce paramagnetic shifts in C n.m.r. spectra. Thus, all sets of shifts in 2,2-dimethylpropan-l-ol varied with concentration of the added shift reagent, except when using the Gd complex where no shift was experienced. In the study of Bu"NH2, Pr"NH2, and n-CjHjjNH2, and upheld shift of the C-2 resonance was observed, but a comparable downfield shift occurred with Bu"OH. Induced shifts of C resonances were utilized in the analyses of the spectra of piperines" and ribose-5-phosphate. ... 

The Aedes aegypti (Diptera Culicidae) mosquito is the primary vector in transmitting dengue and yellow fever. Insecticide use has been the primary method of control of this and other mosquitoe species. Piperine [(T,. S )- -piperoyl-piperidine], is the major constituent in Piper nigrum... 

L-lysine Piperidine alkaloids Piperidine Anaferine Lohelanine Lohehne A-methyl pelletierine Pelletierine Piperidine Piperine Pseudopelletierine Sedamine... 

Alkaloids with the piperidine nucleus, such as pelletierine (Punica grana-tum), lobelanine Lobelia inflata) and piperine Piper nigrum), have a typical biosynthesis pathway. It starts with L-lysine and continues via cadaverine (biogenic amine), A -piperideine and A -piperidinium cations and lobelanine, to be synthesized as lobeline. Piperine is synthesized from A -piperideine via piperidine (Figure 49). For the transformation from A -piperideine to A -piperideine cation, the residue from acetyl-CoA is needed, together with SAM activity in the transformation to lobelanine. Piperine is synthesized from piperidine through the formation of amide. 

Figure 49. Diagram of the pelletierine, lobelanine and piperine synthesis pathway.

Kapil, A. 1993. Piperine A potent inhibitor of Leishmania donovani promastigotes in vitro. Planta Medica, 59 474. 

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